At 13.23 hours on 14 Sep 1939 the unescorted Fanad Head (Master George Pinkerton) was stopped by a shot across her bow from U-30 about 280 miles west-northwest of Malin Head. The master, 33 crew members and eight passengers abandoned ship in two lifeboats, which were towed away from the ship by the U-boat. A prize crew (I. WO Oblt z.S. Hinsch, ObMasch Büsgen, MaschOGfr Schmidt and Ohse) boarded the vessel to take over provisions and to prepare the ship for scuttling.

The crew had been able to send a radio message, which alerted HMS Ark Royal (91) (Capt A.J. Power, CVO, RN) on anti-submarine patrol about 200 miles to the northeast of the reported position. The carrier launched three Blackburn Skua aircraft of 803. FAA-Squadron armed with one 100lb and four 20lb bombs and detached HMS Tartar (F 43) (Capt G.H. Warner, DSC, RN), HMS Bedouin (F 67) (Cdr J.A. McCoy, RN) and HMS Punjabi (F 21) (Cdr J.T. Lean, RN) from her destroyer screen. About 30 minutes after launching the aircraft, the carrier was unsucessfully attacked by U-39 (Glattes), which was herself lost in the counter-attack of the remaining escorting destroyers. After two hours, the carrier launched two sections of three Swordfish aircraft of 810. and 821. FAA-Squadrons and also detached HMS Fame (H 78) (Cdr P.N. Walter, RN) and HMS Forester (H 74) (LtCdr E.B. Tancock, RN) to the scene, but they arrived too late.

When the Skua ("A7M" L2873) crewed by Lt R.P. Thurston and PO James Simpson investigated a ship, they were surprised to find an U-boat alongside a merchant ship and had to drop the bombs immediately at very low level. The small bombs detonated on contact with the water surface and shrapnel hit the aircraft, forcing the pilot to ditch the burning Skua in some distance. Both crewmen survived the crash badly burnt and began swimming towards the Fanad Head, but only the pilot reached her and was rescued unconscious by the injured ObGfr Ohse. The U-boat had crash-dived by the stern and escaped damage, but left another man on the surface, ObMaschMt Hinisch, who swam to the ship. The bombs had detonated so close to the ship that three men from the prize crew were wounded by shrapnel.

Ten minutes after the first air attack, the Skua ("A7A") crewed by LtCdr Dennis Royle Farquharson Campbell (CO of 803. FAA-Squadron) and Lt Michael Charles Edward Hanson arrived at the scene and attacked an object about a mile south of the ship in two passes, but the 100lb bomb was apparently a dud. They reported an attack on a conning tower and observed two men swimming in the water, but in fact the object was very likely the wreck of the first Skua. When U-30 surfaced nearby they had no bombs left and forced it to dive again with strafing attacks. The aircraft was then low on fuel and had to leave the area, after landing on the carrier they found shrapnel holes in the fuselage from their own bombs.

After the aircraft left, the U-boat re-surfaced and tried to get alongside to rescue the prize crew. In that moment, the third Skua ("A7K" L2957) crewed by Lt Guy B.K. Griffiths and PO George Vincent McKay, unaware of the previous actions, arrived and it followed an almost exact repetition of the events that led to the loss of the first Skua. The bomb explosions ripped off the nose with the engine and the Skua fell into the sea. The observer was lost with the aircraft, but the pilot managed to get free, swam to the ship and was taken aboard. U-30 damaged her bow in her third attempt to get alongside and managed to take aboard the five crew members. The pilots initially remained aboard, but jumped overboard when they were told by Lemp that the ship will be torpedoed and were taken prisoner, only moments before the first Swordfish arrived and forced the U-boat to dive by a strafing attack. At 18.20 hours, the Fanad Head was sunk by a G7a stern torpedo from a range of 500 metres. The submerged U-30 was then badly damaged by bombs from the Swordfishs and depth charges from two destroyers, while HMS Tartar (F 43) picked up the survivors and took them to Mallaig, Scotland. The U-boat was attacked until 22.00 hours and managed to escape on the surface one hour later.

On 19 September, U-30 entered the harbour of Reykjavik, transferred the seriously wounded MaschOGfr Adolf Schmidt to the interned German steam merchant Hamm and took her third officer Grohm as replacement aboard. Adolf Schmidt recovered from his wounds, but was taken prisoner when Britain occupied Iceland in May 1940 and transferred to a POW camp in Canada. The two British pilots were landed at Wilhelmshaven on 27 September and taken to a POW Camp in Brunswick.